nbc news that iran was behind a recent series of attempts to disable the websites to several major u.s. banks. now those attacks failed. but another iranian attack nearly shut down a saudi arabia oil company, experts say that type of attack should be a warning to the u.s. >> we don't have that type of security in the financial sector, the oil and gas sector, any of our critical infrastructures. >> leon panetta says that the industry must do more to combat those types of threats. >>> and tragedy on the tracks, we often hear about deadly accidents on our rails. in fact, there were two of them just last week. but how often is there trouble? we break down the numbers of accidents and deaths. >> reporter: we found that transit agencies spend millions every year to try to stop the tragedies. but the problem is not going away. in every one involved, from family members to those killed, to local motorists and commuters, are affected. >> they have it in my mind -- what they look like, what they're wearing. >> reporter: lasting images left in the mind of local engineer. >> they end up getting th